The invention relates to the field of compressive orthoses of the sock type for treating circulatory disease of the lower limbs.
In the present description, the term xe2x80x9corthosisxe2x80x9d is used in its conventional medical sense, i.e. an appliance for applying assistance to a region of the body to mitigate a functional deficiency of the locomotive system, and excluding prostheses which are replacement appliances. A xe2x80x9csockxe2x80x9d is an orthosis surrounding the leg and the foot, it being understood that the sock may extend upwards, where appropriate, to the knee, to the middle of the thigh, or to the top of the thigh, and that the foot is not necessarily completely covered, and on the contrary it is often preferable for the sock to terminate, e.g. level with the base of the toes.
In the present case, the functional deficiency in question is circulatory deficiency of a lower limb, which deficiency is mitigated by applying compressive support, more particularly support that applied degressive compression, i.e. compression that is applied over all or part of the length of the lower limb starting from the ankle and with the amount of compression decreasing with increasing distance from the ankle.
One of the most common diseases to which the invention is advantageously applicable is treating a venous ulcer or a wound that requires compression. The healing of venous ulcers in the leg necessarily requires appropriate and effective compressive support, with compression being a fundamental part of the treatment.
At present, the vast majority of cases requiring such compression are treated using non-removable elasto-compressive socks (NECS) put into place by the practitioner using adhesive elastic strips which are used once only or dry strips which are washable, but which rapidly lose their initial compressive qualities. The dressing is changed every 3 to 10 days, as a function of the amount of exudate produced by the wound, and the average duration of treatment is about 70 days for a varicose ulcer without complications and of area smaller than 15 cm2.
NECS suffer from numerous drawbacks:
the skin must be protected by a plain or moss stitch undersock;
a trained operative is required to put the strip into place, which strip is then left in place for several days;
the pressure applied to the strip is imprecise, depending a great deal on the skill of the operative;
troublesome creases in the strip when walking; and
poor vertical stability of the bandages when walking.
Automatic degressive compression by means of an elastic stocking would be better adapted to such treatment and much more comfortable to patients, while nevertheless being just as effective, therapeutically, as are NECS. However, at present, elastic stockings are used very little for this indication since they are expensive articles. Leg ulcers run a great deal, so the stockings are quickly dirtied and damaged, making the cost of treatment prohibitive since it is always very lengthy, as mentioned above.
An object of the present invention is to remedy that difficultly, by proposing a novel sock-type compressive orthosis (in the sense given above) which satisfies all of the following conditions:
article for single use;
article of low cost;
article easy to handle by a practitioner;
article of one size only;
compressive support effective for the particular disease in question;
compressive support is degressive;
no compression of the foot;
readjustment possible without removing the article; and
compatible with the article being worn continuously, for several days or even several weeks, and in particular when prone (typically at night).
To this end, the orthosis of the invention which is a compressive orthosis of the sock type for treating circulatory diseases of the lower limbs, in particular for providing compressive support to the leg after a venous ulcer, the orthosis being suitable for applying compressive support over all or part of the leg and that is degressive from the ankle, is characterized in that it comprises a knitted compressive tubular portion of varying section constituted by a leg portion of an elastic stocking without a foot or a heel, said compressive tubular portion being extended at its bottom end by a knitted non-compressive tubular portion suitable for covering at least a portion of the foot without compressing it.
According to various advantageous subsidiary characteristics:
the non-compressive tubular portion has reinforcing yarn in its knitting, over at least a portion of its circumference;
the non-compressive tubular portion is made using a plain moss type stitch;
the compressive tubular portion is extended at its top end by another knitted non-compressive tubular portion;
the orthosis is made in the form of a continuous knitted tube of varying section made of non-run stitch that is alternately compressive and non-compressive, the tube being constituted by a sequence of similar individual elements separable by cutting the tube, each of said elements forming an individual sock extending between two cutting-out zones defining the sock and situated in the regions of non-compressive knitting;
in which case, in a first implementation, the individual elements form a sequence of elements disposed in opposite directions, each element being the reflection of an adjacent element about axes of symmetry situated in the regions of the cutting-out zones;
in a second implementation, the individual elements form a sequence of elements disposed the same way round, each element being a copy of an adjacent element representing a shift of a module of length equal to one individual element; and
the knitting of the tube includes at least one breakable thread in each cutting-out zone.